Network monitoring devices, such as monitoring probes, have been proposed to measure performance of traffic flows in LTE networks. However, when a handover for specific user device/user equipment (UE) occurs from the coverage of a source evolved Node B (eNB) to that of a target eNB, although the network monitoring device is able to observe that a handover has occurred, it cannot determine which UE is involved. In other words, it is difficult for the network monitoring device to track user specific tunnels (that is, specific logical connections of users) after a handover. Therefore, when a handover occurs, the network monitoring device may be not able to continue the measurement of traffic flows for a specific UE, especially, when the handover occurs from the coverage of a source MME to that of a target MME.
In view of the foregoing and other problems, it is desirable to provide a network monitoring device which is able to track user specific tunnels by tracking/identifying identifiers corresponding to a user device in Evolved-Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN) of LTE networks when a handover occurs.